Train control



March 3, 1931. s. BUSHNELL TRAIN CONTROL Filed June 28 1924 INVE TOR.

' TTORNEY o v x w m m Tm \D J d J q a 8 B i K J j in, w m

mLot Lu ;...200 EF coz vl t Pr 0L+c0o GLL Patented Mar. 3, 1931 onaraans s. BUSHNELL, or nocnnsrna, NEW YGBK, AssIenon TO Gtmmm wn SIGNAL COMPANY, or nocnnsmnn, NEW YORK mAm CONTROL v. 7

Application filed-Tune 2 8,

This invention relates to automatic traiii' control systems, and more particularly to systems commonly known as the'continuous inductive train-control type.

employs alternating control currents flowing in the track rails-and inductively transmitted from the'track rails'to suitable receiving devices located on the locomotive or other movv vehicle, and these currents act on suitable car-carried apparatus to control the progress of the train in accordance with changes in traffic conditions ahead, as manifested by changes inthe track rail control currents.

In applying this type of train control system to existing railwaysystems,'it becomes necessary to provide for the operation of trains equipped for automatic train control over sections of trackway not equipped for train control operation. It is essential to safe train operation that this change of condition of the train or car-carried control apparatus, releasingvthe train from automatic control, should be made only at points at 'which the train enters unequipped territory. It is evident that if a mere manual actuation of a switch, lever or other means were used to effect this change, the engineer or train operator couldat any time inequipped territory trol and-so proceed with no annoying restrictions asto speed. I i

I n is one, object of this invention to ave a simple and efiicient automatic means for releasing the train from one action ofthe automatic control apparatus at the point where such train enters an unequipped section of trackway, and for again placing the-train under the restrictions of the automatic coir" rails 1" are divided into blocks by the insulat- -ing joints-2, the block. I-and portion-s of trol apparatus when asection'of trackway equipped for train control is encountered.

The control apparatusais usually reset to its active condition by means of the return of the control current which floWs in-the track has been found'inpractice that at certain points along a section of trackway not equ pped for train control, stray currents This type of train control system usually release the train from automatic trainconrails in equipped sections of trackway; It impressed across the railsat theexit end of sometimes flow fo'rshort distances in the track'rails. These stray currents ortran 1924, serial No. 723,048.

sients, as theyare sometimes called, maybe caused by the leakage] ofalternating signal currents from adjacenti track rails to the track rails under consideration,.or they may The effect of these arise from other causes. stray currents, which areusually of short duration in point of train travel, is to reset the car carried train controlling apparatus to its active condition, and therebyto impose ai fimmediaterestriction on the train speed,

up traffic, and causing unnecessary delays and inconvenience.

It isa further objeetiof this invention to provide car-carried means which will act to prevent the resetting of the: car-carriedcoiiing such a distance of travel to reset the control apparatus, such resetting of the control apparatus and subsequent delay in train operation due to stray currentsfiowing over short lengths of the track rails will be avoid-a ed, and more 'en'icient tIZIIII operation will 'result;

Other objects, advantages and desirable features of the invention willibe pointed out orwill become apparent. as the description of the system progresses;

In the drawings,a-section of trackway and the car-carried apparatus equipped "fora fltraiircontrol' system embodying the present .-inve'ntion has been represented in, a conventionaland simplified mannen. f f

Y Refi'erring particularly to the jtrackw'ayequipment in the territory equipped forthe regular automatic train control the track the'adjacent blocks H and J, having been fTrack signal-and train control currents are each block by means of the track battery usually. bringing the trainto a stop,-slowing 3fandthe secondarywinding ofthe transformer 4t as shown. The primary winding of this transformerfis energized through the Lyn contact fingers 5 and 6 of the track relay 7 and the transformer8 which is connected across, the transmission line 9 as clearly shown in the drawings. The track relay 7 is con nected across the track rails 1 at the entrance end of each block by the wires 10 and 11. This track relay 'Zmay be of any suitable type, but in the specific emboeimcnt shown is preferably of the direct current type.

Wayside" signals of the semaphore, light signal or any other suitable type, operated by the track relay 7, may or may not be used. For the purpose of illustration, semaphore signals Z of the type common in railway signal practice have been conventionally shown at the entrance end of each block;

The means for operating these semaphore signals from the track relays 7 have not been illustrated as these means are clearly understood by those skilled in the art, and as these means form no part of the present invention.

That portion of the traclrway which is not equipped for automatic train control is conventionally illustrated and referred to as non-control territory, andmay be a siding,

a branch. line. a portion of: the main line to set the car-carried apparatus to its noncontrol condition. In accordance'with this invention an excess amount of current is supplied to the track rails, or to a wave wire or loop adjacent to the track rails and producing a flux field in the same direction as that of a field produced by current fl wing in the track rails, at a point on the trackway where the change from traincontrol to non-train control territory is made. As

shown, a short section of the track rails J,

adjacent to the non-control territory is provided, this section being hereinafter referred to as the excess energy section. An alternat ing train control current of the same frequency asithat used in blocks H and Lbut of an appreciably higher voltage, is supplied to the track rails of this excess energy sec tion so that considerably more current will flow in the rails in section J'than in the rails of blocks H and If This current in section J is supplied to the rails at thev exit end of the section by the secondary winding of the transformer 18, whose primary winding 'is energized from the transmission line 9.

In train control territory, the presence of.

a train in a given block cuts off the train control current behind the train in that block and in the next block in the rear. In order ployed.

that the train control current in the blocs I may reflect trafic conditions, and may be dependent on the presence or absence of a train in the excess energy section J or in the block K, i't-is proposed to provide the er:- cess energy section J with a track relay l6, andthe block K immediately ahead with a track relay X, the two sections J and K being preferably at least as long as safe braking distancesfor a train running at speed. \Vith a train in either bloc K or section J, the line relay 1 will be deenergized, cutting off the train control current from the block I, and thus making this a caution block.

A railway vehicle has been conventionally represented by the wheels and axles 19 in the block H. In front of the leading axles, over and in inductive relation to the track rails 1, are mounted two receiving coils 20, having their windings connected in such a way that currents induced therein by currents flowin opposite directions in the two track rails will be additive. Thesercoils may or may not be mounted on laminated iron cores. W hen analternating current flows in opposite directions in the track rails, a current will be induced in these coils in accordance with the laws of electro-magnetic induction.

The windings of the receiving coils 20 are connected to a main car relay MR through an amplifier A by means of a circuit which may be traced as follows :-From the receiving coils 20, wires 21 and 22, contact finger 23 of push button relay PR, wires 24:, 25 and 26, input circuit of amplifier A, wires 27 and 28 back to the receivingcoils 20; the amplified currents being carried to the main car relay MR by wires 29 and 30. A tuning condenser T is connected across the input circuit of the amplifier A as shown. The capacity of this condenser is of such a. value that the input 'circuitwill be tuned to the frequency of the train control current.

The amplifier A, conventionally illustrated in the drawings, is preferably of the type which acts to respond to weak current impulses in its inputcircuit and to produce more -'powerful currents in its output circuit. This amplifier may be of the vacuum tube type, although any other suitable type of amplifier may be used. 7

A rotating shaft 31 is geared or otherwise driven from an axle of the vehicle, the con nection of this shaft to the axlehaving been represented by adot and dash line. Mounted on this shaft area worm gear 32 and a centrifugal speed'r-esponsive device or centrifuge F. This centrifuge has been illustrated in a conventionalform for the sake of simplicity, it being'understoo d that any form of centrifuge adapted to this type of system may be em 7 The centrifuge F illustrated consists of acollar 33 fixed to the shaft 31 and a collar. 34 which is movable on this shaft.

: These collars are urged apart by, the coiled tween the'collzirs 38'and v and thus rocking the speed shaft fQthrdugh rod 59 connectsan intermediatepointof the the lever 41. p v V The wormgear 32 engages a worm wheel 43 which isconnectedby the pinion 4A: to a gear wheel 45. A pinion-46 is rotatably carricd on a movable arm 4-7. this arm beino' 'ourna-led on thesh'aft of. thegear wheel d5 in suclia manner that the pinion 46 is in engagement with the gear wheel 45 regardless of the positionof the arm' f'f. The arm 47 is normally held in the position shown bythe cam starter magnet'GS which draws this'arm down against the pull of ia spring 48.

Directly over. and in line with the pinion 46 is a mutilated gear 49 fixedly secured to a distance shaft 50. The distance shaft 50 carries a special cam, 5l,and a distancecain, 52. The cam 52 operatesto open normally closed contact fingers 5d and 55 after a given distance of car travel from the point at which the distance shaft 50 is started by the deene-rgizati-on of the cam starter magnet CS; The contact finger Mis resilient, and is biased to be retracted from the stationary Contact finger 55.;The Contact tinge/rte carries an arm and a roller as shown, the roller bearing against the edge of the distance cam 52 sothat the contact finger arenormallymaintained closed by this cam :A spring 56 is provided for normally holding'the distance shaft 50111 the position shown, and for returning it to this position when the pinion 46 is disengaged fgom themutilated gear49. The purpose of the distancecam 52 and its associated contacts will become apparent as the desco'iption progresses. v

The cam 51 is specially shaped and oper ates one end of a floating lever57', theiother end of whichis moved by a lever58 fixed to thespeed shaft 42; i It is evidentthat the movement of any intermediate. point on the floating lever 57 will be dependent on a funcitio'n' of the speed of the vehicle' and its'dis tance oftravel from the point at which the distance shaft 50 was started. A connecting floatinglever '57 to: a: camv 60. This cam is biasedby spring 1, andop'erates to open Ltrack rails wlllmduce currents in the rethe normally closed contact fingers 62 similar'to the contact. fingers 54 and 55, under certain conditions of speedand'of distance of travel from a givenpoint. I

"of the engineer or train operator. This push button operates when depressedi'to close ajcircuit'through the push button relay PR, which is preferably mounted in-anapparatus hous- H and operate to make and brealecircuits for the car-carried apparatus as hereinafter described. These relays may be'of any suitable type, and are provided with movable contact ;-nngers which are-biased- "by springs counterweights or othermeans, so that the fingers move to a predetermined position when the relays are-de-energized. The contact fingers of the main relay are preferably mounted on vertically arranged axes so that their motion will be unaffected-by: the vibration of the swaying of the train. 'Ihe non-control relay NO is of the slow-acting type, that is,

this relay is'so constructed-and arrangedthat it will i not release its contacts immediately on the de-energ ization of its windings. The. purpose of this slow-acting feature will be;

brought out in another part of the specificat on.

* din electro-pneumatic valve EPV is .pro-

videdand may be of any suitable typeadapted for train control-practice; It ispreferably "or atype which, when de-energized, will act to effecta brakingiaction on the train by directly venting the brake pipe pressure, by operating the usual engineers brake valve or in any other suitable manner. As the specific type of electro-pneumaticivalve used is immaterial, aconventional form of valve has been represented, and it will be understood that any other type of electro-pneu- -matic valve'or brake control apparatus might be used without departing from the spirit of the invention. o 1 I -i The cab signals G and L are provided, be

ing operated by a contact finger of the main relay MR. These cabsignals may be of any suitable type and are preferably light signals, their-indications being designated "by 'colors,.letters or by any other suitable means,

All-devices and controls have been shown in their'normal position in the drawings.

Opei-ati0n..Assuming that a train is trav-' eling over a block in which clear traffic conditions exist, that is,that no train is located Y in the block under consideration or in the next block in advance, the train control current flowing 1n oppositedlrections 1n the two so i ceiving coils 20, which currents will beamp'lified by theamplifier A and impressed on the tion, .andthe contact finger 81 maintaining an energizing circuit for the cam starter magnet CS, which circuit may be traced as follows :From the battery terminal B,

through contact finger 81 and front contact be the opposite terminals of a battery. With the cam starter magnet CS energized, th distance shaft will be in its normal position as shown, and the contact fingers 54:, 55 and 62 will be closed. The contact fingers 62 will maintain the electro-pneumatic valve EPV energized through a circuit which is obvious, and the train may proceed without restriction. The contact finger 76 of the noncontrol relay NC will be in its retracted position and the contact finger 79'of the main relay MR will be in its attracted position as shown, maintaining a circuit to, and so displaying, the high speed cab signal G, which circuit is obvious from the drawings. V

The speed and distance cam may be so arranged and constructed that its contacts 62 open if a maximum speed of, say, 60 miles per hour is exceeded. This opening of contact 62 ole-energizes the electro-pneumatic valve EPV and causes a-n automatic brake application which remains in effect until the train speed is reduced below the maximum speed limit of 60 miles per hour.

Assuming that a train is located in block '1, its wheels and axles will shunt the train control and signal currents from the rails in block I, de-energizing the track relay 7.

This cuts off the train control current from fying the engineer or train operator that he is entering'a caution or danger block. The releasing of the contact finger 81 de-energizes the cam starter magnet GS, causing the engagement of the pinion' lfi with the mutilated gear 19, and the consequent movement of the distance shaft 50. This movement of the distance shaft 50 causes the special cam 51 to move the floating lever 57, thereby imposing more and more restrictive speed limits'upon the train throughrthe speed and l-"distance cam 60, as the, trainprogresses into a the cautionblock. When the distance shaft 50 has turned through an angle of 180 'degrees, the'mutilated portion of the gear 49 is opposite the teeth of the pinion 46, and no furtherrotation is imparted to the distance shaft 50. At this point the special cam 51 holds the floating lever 57 in its extreme low speed position, and the train may proceed only at a minimum speed of say, 15 miles per hour until traflic conditions ahead have become more favorable. The contact 5a of distance cam 52 is also opened but only after a certain distance'of travel, assumed to be 500 feet. The purpose of this distance cam with its associated contacts will'become more apparent as the description progresses.

New assuming that as the train under consideration progresses under the low speed restriction just described, the trafiic conditions ahead become more favorable; that is, that the advance train passes out of the block I. The train control current now returns to the rails in the block H by the reenergization of the track relay 7. The receiving coils 20 pick up current from the rails and the main car relay MR is energized, lifting its contact fingers 66, 79 and 81. The lifting of contact finger 7 9 energizes the high speed cab signal G through a circuit which is obvious, informing the engineer or train operator that he may now proceed without further low speed restriction. The lifting of contact 81 re-energizes the cam starter magnet CS, disengaging pinion 46 from mutilated gear 49, and allowing spring 56 to return thedistance shaft 50 to its normal position. This'closes the contact fingers 5A and 55 of the distance cam 52 and "allows the special cam 51 to return to the position shown in the drawings at which high speed restriction only is imposed.

. It is obvious from the above description of the normal operation of the train control apparatus that the engineer is immediately informed when he enters a caution block, or when another dangerous condition, such as a train or a broken rail, exists either in the block in which he is located or in the next bloclrin advance. It is also clear that the engineer is immediately informed when trafficcondltions ahead become more favorable .so that he may proceed at a higher speed.

Assume now that a train is progressing under clear traffic conditions in block 1,"-

which isthe last block in a section of trackway equipped for automatic train control of the type under consideration. The engineer, by means of way side indications or from his knowledge of the trackway equipment, will find that he must set the car-carried train control apparatus to its inactive condition, as he is about to travelover a section of trackway which is unequipped for automatic train control. 7 On entering the excess energy section J, the engineer depresses the push button PB. This completes a circuit to the push button relay. PR, causing its contact fingers 23, 6 k and 65 to be attracted.

The opening of theback contact of finger 23 without train control restriction.

inserts ,aresistance B into the circuit fro n the recelv ng co1ls21'to the mam car relay j ME. 'AS a comparativelyheavy current is flowing in the rails ofthe excess energy sect on J, this insertlon of the resistance B into the clrcu t of the receiv ng COllS does not diminish the amount of energy supplied to nal B, through contact fingers '66 of the main relay MR-,wire67, contact finger 64 of the push button relay PR, wires 68 and 70, winding of the non-control relay NC to the battery terminal C. The energization of the.

non-control relay NC, causes its contact fin- ;gers 73', 75, 7 6 and .77 to be attracted. The

non-control relay NGis of the slow acting type and maintains its contact fingers in their attracted positions for a short period after the contact finger 6 L is released. The engineer immediately releases the push button PB, retracting the contact fingers 23, 64:

and Goof the push button relay PR. As

the contact finger is retracted, it closes a stick circuit to the non-control relay NC, which vcircuit may be traced as fOllOWSZ' Frointhe battery terminal B, through contact finger 65 of thepush button relay PB, wire 71, contact fingers 54 and 55 of the distance cam 52, wire 72, contact finger-73 of the non-control relay NC, .wiresia and and winding of non-control relay NC to the battery terminal C. The train may now proceed in non-control territory without further restriction for the reasonthat the con tact finger 75 of thenon-control relay NC is attracted, energizing the electro-pneumatic valve EPV through a circuit which is obvious from the drawings and thus preventing an automatic brake application. The contact finger 76 is also attracted, displaying the non-control cab signal 80 and thus informing the engineer or train operator that he may proceed in unequipped territory tact finger. 77 of the non-control relay NC is in its attracted position and when the main car relay MR drops its contact finger 81, due to lack of train control current'in block K, a circuit is completed to the cam starter magnet CS, maintaining this magnet energized and the distance shaft 50 in its normal position as shown. This circult to the cam starter magnet CS may be traced as follows :-From' the battery terminal B, through the back contact of finger 81 of the main relay MR, wire 82, front contact of finger 77 of the non-control relay NC, wire I 83- and the winding of cam starter magnet CS to the battery terminal The con- When the pushbutton PB is depressed andv the non-control relay NC is energized as the train enters the. excess energy section J, it will be observed that the cam starter magnet GS is de-energized for the reason that contact finger 77 of the non-control relay NC and contact fingerSl of the inainrelay MR are both in their attracted positions. The

cams 51 and 52 will therefore be initiated and 1f the excess energy section. were more than .500 feet in length, the cam 52 would open its contact fingers 5 5i and 55 so breakingthe sticlrcircuit to and de-energizing the noncontrfol relay NC. Inorder to avoid this deenergization of the non-control relay,the ex cess energy section J islessthan 500 feet in length. I 1

iffhen the train returns to a section of trackway which is equipped for automatic traincontrol, the receivingcoils 20 again have currents induced thei'ein'which act to energize the maincar relay MB. This causes said 81. The closingof-v the front contact finger 81 causes the de-en'ergization of the cam starter magnet CS and the rotation of the distance shaft 50. After the train has. traveled a given distance, assumed to be 500 feet,"the,distance c'am. 52 opens its contact fingers 54k and 55, breaking the stick circuit to the non-control relay NC, which then retracts itscontact fingers 73, .1 5, 76 and 77.

relay to attract its contact fingers 66, 7 9 and lVhen the contact finger T7 of thenon-control'i 7 relay is retracted, a circuit to'the canistarter magnet CSthrough the contact finger 81 of the main car relay MR is "again completed, this circuit being obvious from the drawings, andthe distance shaft 50 is returiiedto its normal position; The car-carried train controlapparatu s is now in its active condition and the trainv may proceed in the equipped section of traclrway under the. restrictions imposed by the automatic train control sys 't'em as'described above. I

car-carried control apparatus may be set to I its active condition when the train returns to equipped territory regardless of the condition In order tint the ofthe first equippedblock encountered, that 1s, regardless of whether or not there is train controlcurrent flowing 111' the tracl-z rails in this block; a short, permanently energized section oftrackway may be provided at each point. where the train passes from an 1111'"- equi pped to an equipped section oftrackway. This permanently energized section of track- Way will operate to re-cnergize the main relay MR, thereby de-energizing the cam starter magnet CS and breaking the stick circuit to the non-control relay NC, as described above.

(in re-entering 'a section of trackw'ay equipped for automatic train control, the enginer cannot avoid the restrictions of the car carried train control apparatus by depressing circuit for relay NC is broken at contact linger 66 of relay MR, since with relay PR up, resistance It is in circuit with the relay hilt, and such relay can pick up only with excess energy. Thus the relay NC drops at once, instead of beinglater dropped by member as above'described, so to de-energize magnet CS and impose a restriction on the car. This prevents the abuse of the push button relay by the engineer or train operator to avoid the restriction of the automatic train control apparatus,

Now assume that a train is proceeding over a section of trackway unequipped "for automatic train control, and that a stray trackway current isencountered, said trackway current arising from leakage or from any other cause. 7 l1- such current flows through the track rails in multiple, the coils 20 are substantially unaffected, while if the flow is in series, the receiving coils 20 are immediately energized causingthe energization of the main relay MR and the attracting of its contact linger 8 1. This effects the de-energization of the cam startermagnet CS, starting the rotation of the distance shaft/5O and the distance cam 52. This will not however, cause an immediate de-energization of the non-control relay NC, for the reason that the distance cam 52 does not open its contact fingers 54 and 55 and so break the stick circuit to the noncontrol relay NC until after the train has traveled a given distance, assumed to be 500 feet, with its receiving coils 20 in their energized condition. On the assumption that these stray currents or transients which may be picked up in unequipped sections of trackway will be of short duration, the protection afforded by the distance cam 52 is adequate to carry the train across such temporarily energized sections without the de-energization or" the non-control relay NC, and a subsequent automatic brake application. l/Vhen the re-' receiving coils 20 are no lon er energized by these transient currents, the main car relay MR again drops its contact finger 81, and the cam starter magnet CS is re-energized, causing the return of the distance shaft 50 to its normal position.

It should be noted that the engineer or train operator cannot, in the present system, avoid the restrictions or" automatic train control operation by depressing and fastening down the push button PB. When the train is traveling over a section I of trackway equipped for automatic train control operation and push button 'PE is depressed, the insertion of the resistance R in the circuit oithe receiving coils 20 will cut down the current received from the rails to such an extent that the main car relay MR will be de-energized,

causing the de-energization of the cam starter over apparatus.

magnet CS, and thus imposing a low speed restriction. The elements of the main relay MR and the non-control relay NC are so'designed and adjusted that'the contact finger 66 of the main relay will open its front contact before the contact linger T3 of the non-control relay has closed its front contact, and, as a result, the stick circuit for the non-control relay may not be completed while the train is traveling in equipped territory.

Also, it the engineer attempts to prevent the relay MR from picking up upon re-entering train control territory, by picking up rela T PR thus to prevent startin saeed re- 7 L D stricting cam 60, the opening of contact 65 will drop relay NC to de-energize CS and thus require him to again release the push button PE in order to proceed unrestricted.

From the foregoing description it is seen that an automatic train control system has been provided in which control influences are continuously transmitted to the moving vehicle, and its progress along the trackway is regulated by car-carried apparatus con trolled by said control influences. It is also seen that a simple and eliicient means for eifecting a change over from train control territory to sections of trackway unequipped for train control has been provided, together with means for preventing the abuse by the engineer or train operator or" such change Further, it is evident that means have been provided to prevent unnec essary delay of train operation in territory unequipped for automatic train control, due to stray currents or transients existing in the rails in such unequipped territory.

It is to be understood that the present invention is not limited to the specific details described, and further, that many additions, modifications and changes could be made without departing from the spirit of the invention. F or instance, means for operating the railway vehicle with either end leading could be provided, and automatic or manual switching means for said reversing apparatus could be used. Also, the main car relay could be of the polyphase type, imposing high, medium and low speed restrictions on the train instead of simply high and low speed restrictions, and many other modifica tions, combinations. or additions might be made without departing from the spirit of the present invention.

What it is desired to secure by Letters Pat cut is 1. In an automatic train control system for a railway having a portion of its trackway equipped for automatic train control and a portion not so equipped, the combination with car-carried brake control apparatus controlled from the trackway in equipped territory in accordance with traffic conditions ahead; of means rendering said apparatus ineffective while the train is travelling in un- I porarily energizing said second relay as the train moves from an equipped section to an unequipped section of trackWay, and means for maintaining said second relay energized after it has been once energized until said iriaiircar relay is energized throughout ap car-carried brake control apparatus includgiven-distance of train travel. 7

9. In an automatic train control system, car-carried apparatus for controlling the progress of a vehicle in response to influences corresponding to tra-flic conditions ahead including a main car relay and a distance-operated cam, said cam being normally maintained in an initial position by the energiza tion of a magnet, and a second relay for rendering said control apparatus inactive, said magnet being maintained energized when said maincar relay is deenergized and said second relay senergized, said magnet being also maintained energlzed When said main car relay is energized and said second relay is deenergized; c 10. In an automatlc train control system for a railway having sections of its trackway equipped for automatic train control and sections not so equipped, car carried apparatus including a main car relay for controlling the brakes 0t avehicle in response-to infiu ences transmitted from the trackWay in said 11. In an automatic train control system,

car carried apparatus-including a car relay for controlling the brakes of a vehicle in accordance, With influences corresponding to traffic conditions ahead, a second relay having a stick circuit, contacts in said stick circuit, and a distance measuring device adapted to be driven from the carvvheels for opening said contacts only after a predetermined distance of travel, said device being set into operation by the energization of said car relay.

12. In an automatic train control system for a'railway having a section of its track- Way equipped for automatic train control and portions not so equipped, car-carried apparatus for controlling the brakes of a vehi- 016 in accordance With influences corresponding to trafiic conditions ahead, a relay for rendering said control apparatus inactive having a stick circuit and a pick up circuit, said stick circuit including contacts of acircuit controller, which contacts are closed only When said circuit controller is in its non-operating condition, a main car relay energized on the entrance of the Vehicle into said equipped sections of trackWay, and other contacts for, saidstick circuit which are opened onlyrafter a predetermined distance or vehicle travel fronithe point at which said "lain car relay is energized. .7 V r 13. In an automatic train control system,

ing a main car relay, a distance element initiated by the de-energization of an electromagnet, two energizing circuits for sald electro-magnet including respectively a front contact and a back contact of said main car relayand a nonrontrol means for maintaining said brake. control apparatus inactlve control means controlled by thecarrelay, a

non-control relay for removing the train control means from control by said car relay, a pick up circuit for the non-controlre lay including a normally open manually operated contact and a front point of the car relay, and a stick circuit for the non-control relay including a normally closed manually operated contact, and a distance operated contact. r l

I 16. In atrain control system, car-carried apparatus including, a car relay controlled in accordance'witli 'trackivay conditions, train control means controlled by the car relay, a non-control relay for removing the train control means from control by said car relay, a pick up circuit for the non-control relay inclu ling a normal open manually operated contact and a front point of the car relay, a stick circuit for the non-control relay includ ing a normally closed manually operated contact and a distance operated contact, and trar'i'iccontrolled means for initiating the distance operated contact.

17. In an automatic train control system, car-carried train control means including, a main relay, a non control relay, an energizing circuit for the non-control relay, and contact means for changing the condition of such cmequipped territory comprisin ceiving coils, amplifying means, and an electro-responsive device cooperating with a trackway circuit which supplies energy to the receiving coils continuously except under unfavorable traffic conditions; means for maintaining said brake control apparatus inactive while the trainis travelling in unequipped territory comprising, a normally deenergized relay, an energizing circuit for said relay including a contact closed only it said electro-resgonsive device is energized and a normally open contact of a manually controllable circuit controller, said circuit controller when operated rendering the receiving coils, amplifying means and electrolcSPOllSlVG device incapable of maintaining said contact of the electro-responsive device closed in response to the largest amount of current llowing in said trackway circuit in equipped territory, a trackway circuit at the entrance to an unequipped section of trackday and supplied with an excessive amount of currentsuliicient to maintain'closed the contacts ot the electro-responsive device with said circuit controller in its operated position, said relay being deenergized when the vehicle is travelling in unequipped territory unless said circuit controller is restored.

3. In an automatic train control system for a railway having a portion of its trackway equipped fiorautomatic train control and a portion not so equipped, the combination with car-carried brake control apparatus controlled from the trackway in accordance with traffic conditions ahead, of means rendering said apparatus ineffective while the train is travelling in unequip ed territory comprising, a manually operable circuit controller, a stici: relay which when energized will render said apparatus inel'i'ective, a pick up circuit and a stick circuit for said stick relay, said stick circuit including a contact closed only when said manually operable circuit controllcr is in its normal position.

4. In an automatic train control system for a railway having a portion of its tracln way equipped for automatic train control and a portion not so equipped, car-carried brake control apparatus continuously controlld by "v received from the traclrway through i receiving circuit, means for render In an automatic train control systemfor to said unequipped portion ing said brake control apparatus inactive while the train is travelling in unequipped territor comprising, a manually operable circuit controller, a resistance inserted in said uned receiving circuitby the operation of said circuit controller, a relay initially energized by said circuit contr-oll r and in n tuined energized by the rele se Sill-C cuit controller, said relay operating w energized to render said brake controliin apparatus i" (T active p rovided. sufiicient energy sup alied to said receiving circuit to counteract ti effect of said resistance, an insulated section of track rails adjacent of traclrway, supplied with an excess amount of energy, th reby supplying said sufhcient amount of energy to said receiving circuit. 7

5. lnan automatic train control system for a railway having a portion of its trachway ped for automatic train control and a so equipped, car-carried brake control sp nius continuously controlled by energy received from the traclzway through receiving equipment, a manually operable device acting when operated to reduce the sensitiveness of said receiving equipment, means a; the entrance to such unequipped portion of trachway for delivering an excessive amount of energy to said receiving equipment, and means for maintaining aid brake control apparatus inactive while travelling in the an-equipped portion of tracltway, last mentioned means being initiall actuated byoperation of said manually operable device and hei held actuated only if said device isin its normal non-operated condition.

a 6. In an automatic train con rol system for a railway having a portion of its trackway equipped for automatic train control and a portion not so equipped, car-carried apparatus for automatically controlling the movement or a train in accordance with control infiuences corresponding to traiiic conditions ahead, a non-control device for rendering said automatic control means inactive when the train is travelling in said unequipped territory, and means for rendering ineffective said non-control device upon the return of the vehicle to equipped territory only after a given distance of vehicle travel.

7. In an automatic train control system for a railway having a portion of its track vay equipped for automatic train control and a portion not so equipped, car-carried apparatus for controlling the movement of a train in said equipped territory comprising a distance element, a v relay for maintaining said car-carried control apparatus inactive when the train is travelling in said unequipped territor and means inoludingsaid distance element for rende ing said relay ineffective only after a given distance of travel in said equipped territory. 7

8. In an automatic train control system for means openingsuch circuit after a given distance of traveliupon the energization ofsaid main relay.

, 19. Railway vehicle carried. apparatus comprising a circuit receiving energy from the trackway and including a normally shunted resistance,a-main relay controlled by said circuit and responsive to the energy normally received therein when said resistance is shunted but not responsive when the shunt'aroundthe resistance, is removed unless the circuit receives a greater'amount of energy from the trackway, a cut-out relay, a pick-up circuit for said cut-out relay including a normally open circuit controller and a contact closed only when said main relay is energized, a stick circuit for said cut-out relay including a contact controlled by the energization of said main relay, and manually operable means for simultaneously opening the shunt around said resistance and closing said normally open circuit controller.

20. In an automatic train control system,-

car-carried control apparatus including a normally deenergized stick relay, a manually controllable circuit controller having a normally open contact and a normally closed contact, a pick up circuit for said stick relay including said normally open contact, and a stick circuit for said stick relay includingsaid normally closed contact. I i

,21. Ina train control system, car-carried apparatus including, a car relay controlled in accordance with trackway conditions, train control means controlled by the car relay, a non-control relay for moving the train control means from control by said car relay,

a pick up circuit for the non-control relay including a normally open manually OOIl-.

trolled contact and a front point of the car relay, and a stick circuit for the non-control.

relay including a normally closed manually controlled contact. Y 7

22. Railway vehicle carried apparatus comprising a circuit receiving energy from the trackway, a circuit controller having a normal position and manually controllable to a reverse position, a main relay controlled by said circuit and responsive to the energy normally received therein if said circuit controller is in normal position but not responsive when said circuit controller is in reverse position unless the circuit receives a great amount'of energy from the trackway, a cut-out relay, a pick-up circuit for said cut-out relay closed only when said main relay is energized and said circuit controller is in reverse position, a stick circuit for said cut-out relay effective only when the cut-out relay is energized and said circuit controller is in normal position, vehicle governing mechanism controlled by. said main vrelay, V

and means for removing said mechanism from control by said main relay when said cut-out relay is energized.

23. Railway traflic controllingapparatus comprising, a main relay controlled from the trackway, a controller. having a normal posi tion and manually controllable to a reverse position, a cut-out relay, a pick-up circuit for said cut-out relay closed only when said main relay is energized and said circuit controller is in reverse position, a stick circuit for said cut-out relay effective only when the cut-out relay isenergized and said circuit controller is in normal position, vehicle governing mechanism controlled by said main relay, and means for removing said mechanism from control by saidniain relay when said cut-out relay is energized. 1 y

In testimony whereof I aflix my signature.

CHARLES S. BUSHNELL. 

